1. Field of the Invention
This invention relates to digital electronic watches, and more particularly to a digital watch having battery select circuitry which connects the first battery to the digital watch's oscillator and high frequency dividers to power same during the A.M. period and connects a second battery to the digital watch's oscillator and high frequency dividers during the P.M. period and connects both batteries to the digital watch's oscillator and high frequency dividers when the user of the watch desires to display the horological information.
2. Description of the Prior Art
In the art, the LED digital watch and the Liquid Crystal Display digital watch with an illumination light have employed two batteries (each supplying 1.5 volts) to power said watch's oscillators and electronic circuitry. Use of two batteries wasted power, i.e., only one battery, 1.5 volts, was needed to power the watch's oscillator and electronic circuitry when the LED display elements were not illuminated. These prior art digital watches were using two batteries to supply the voltage to the oscillator and electronic circuitry all of the time when the voltage from only one battery would have been sufficient. One solution to this problem was described in patent application Ser. No. 576,760 filed May 12, 1975, entitled, "Digital Watch with Oscillator/Divider Power Selection Circuitry," by Norman E. Moyer. The "Power Selection Circuitry" as described in Ser. No. 576,760 powers the digital watch's oscillator and electronic circuitry with one particular battery and then when the display is interrogated both batteries are used. The drawback with this invention is that it wore out the one particular battery that was being used all the time to power the oscillator and the electronic circuitry of the digital watch. That is, one battery was constantly being used and therefore wore out much sooner than the other battery. The present invention solves this problem by switching the batteries; the first battery is used to power the oscillator and high frequency dividers during the A.M. period and the second battery is used to power the oscillator and electronic circuitry during the P.M. period, naturally if the user interrogates the horological information during either period both batteries will be used to power the oscillator and high frequency dividers because one battery when under load cannot supply enough voltage to operate the oscillator and high frequency dividers.